The overall objectives of the total project include the elucidation of the mechnanisms by which specific factors to eukaryotic cell physiology, such as nutritional stress and biochemical events during the cell cycle, affect the expression and control of cellular transcription. The anticipated goals for the current year include: 1. The isolation of poly(A) mRNA from G1 and S-phase of HeLA cell cycle and the synthesis of radioactive cDNA from these mRNAs. 2. The isolation of DNA, histones, and nonhistone proteins (NHP) from HeLa cells during G1 and S-phases of the cell cycle. 3. The in vitro reconstitution of chromatin from DNA, histone and utilizing NHP from either S-or G1 phases of the cycle. 4. The in vitro transcription of the above reconstituted chromatin utilizing mercurated UTP, and the selective isolation of newly transcribed RNA. 5. The detection of selective cell-cycle-specific mRNA transcripts from the above reconstituted chromatins using RNA-DNA hybridization. 6. The isolation of Cell-cycle-specific HnRNA; the synthesis of cDNA towards these HnRNA and ultimate use in the hybridization experiments above.